Blower wheel having interior motor cooling ribs

Abstract

A blower wheel for an electric motor driven fan includes an impeller in concentric alignment with a back plate. The back plate has an interior sleeve with a plurality of inwardly directed ribs that define a motor receiving circle in which a motor is disposed. Gaps between the ribs form a cooling shroud about a motor rotor such that when the blower wheel is rotated the plurality of ribs force high velocity air through the gaps and over the outside surface of the rotor. The blower also includes a shroud positioned about the blower wheel and motor having inlet and outlet air openings.

I claim: 
     
       1. A blower wheel for an electric motor driven fan, said blower wheel having an axis of rotation and including a back plate and an impeller, said back plate having a first annular disk and an interior sleeve integral with said first disc, said interior sleeve having an outer ring with an inner surface from which a plurality of inwardly directed ribs extend to define a motor receiving circle, said ribs also defining a plurality of gaps containing air that is directed at the periphery of said motor receiving circle when said blower wheel rotates about said axis of rotation,   said impeller having a second annular disc and a plurality of blades carried on said second disc and projecting parallel to said axis of rotation,   said back plate and said impeller being joined together in concentric alignment.   
     
     
       2. A blower wheel as defined in claim 1 with said back plate and said impeller having interengaging means for joining said back plate and impeller together. 
     
     
       3. A blower wheel as defined in claim 2 wherein said means for joining includes a plurality of pins carried in said blades opposite said second disc, and a plurality of openings in said first disc, with said pins positionable in said openings when said back plate and impeller are brought together. 
     
     
       4. A blower wheel as defined in claim 3 with said impeller blades ultrasonically welded to said back plate first disc. 
     
     
       5. A blower wheel as defined in claim 1 with said impeller blades ultrasonically welded to said back plate first disc. 
     
     
       6. A blower comprising a motor and a blower wheel, said motor having a stator carried on a mounting plate and a rotor positioned around said stator, said blower wheel having an axis of rotation and including a back plate and an impeller,   said back plate having a first annular disk and an interior sleeve molded integrally with said first disc, said interior sleeve having an outer ring with an inner surface from which a plurality of inwardly directed ribs extend to define a motor receiving circle in which the ribs are in fixed, abutting relation with the rotor, said ribs also defining a plurality of gaps containing air that is directed at the periphery of said rotor when said blower wheel rotates about said axis of rotation,   said impeller having a second annular disc and a plurality of blades carried on said second disc and projecting parallel to said axis of rotation,   said back plate and said impeller being joined together in concentric alignment.   
     
     
       7. A blower as defined in claim 6 with said impeller blades of said wheel ultrasonically welded to said backplate first disc. 
     
     
       8. A blower as defined in claim 7 including an exterior shroud positioned about said blower wheel and motor, said shroud having an inlet opening at said impeller second disc into the interior of the shroud between said blades and said motor rotor, and   an outlet opening at a plurality of said blades outer ends.